EXPERIMENT, STATION REPORT. 639 



under loO'Se bark scales. But so used, the strength oi the mix- 

 ture was generally in the neighborhood of i pound in i gallon 

 of water, and I doubted \'ery much the value of so' weak a solu- 

 tion as I pound in 6 or 7 gallons of water. My personal work 

 was, therefore, done with a solution O'f i^ pounds of 97 per 

 cent, to 98 per cent, caustic soda, in 2 gallons of water. With 

 this I sprayed two badly infested lilac bushes in the garden, 

 and the following trees in the Exi>eriment Orchard. March 9th, 

 1904: 



Dwarf Pear, 1; Dwarf Duchesse Pear, 1; Lawrence Pear, 1; Greens- 

 borough Peach, 2; Elberta Peach, 1. 

 Trellised Apple, 1. 

 Nectarine, 1. 

 Japanese Chestnut, 1. 



All of these trees showed a characteristic bluish tinge when 

 dry, testifying to^ the thoroughness of the application and. later, 

 the bark showed the clean, polished appefiu'ance already re- 

 ferred to. Oil the badly infested lilacs all the old scurf was 

 cleaned off before the leaf buds unfolded, and on the surface so 

 cleaned the real hibernating forms, — the black, nearly full- 

 sized scales, — were seen in fine relief. Almost all the insects 

 beneath these scales were plump and healthy, and during the 

 latter part of June a full brood of larva? testified that appear- 

 ances had not been decei)tive. 



Of the treated trees the dwarfed pear died almost tO' the 

 ground and remained fre from scales until August, neither 

 facts being- attributable to the soda. The Dwarf Duchess de- 

 veloped a small brood of larvje late in June; but [probably no 

 fewer than the small infestation would have sup]>lied other- 

 wise. On the Lawrence pear, new sets w'ere found June 27tli, 

 and these increased at such a rate that a summer apyjlication be- 

 came necessary July 13th. 



Of the peaches, one of the Greensboroughs died without mak- 

 ing a start, but the death was not chargealile to the soda; the 

 other was only slightly infested, yet on June J7th. larvc'e and 

 recent sets were present, and increased at such a rate that as 

 early as Julv 8th, it was sprayed tO' check development. The 

 Elberta also died before scale breeding began, although it did 

 make a start. 



The Japan Chestnut was treated only to see whether the 

 caustic would have any appreciable effect upon it, and the 

 answer was in the negative. 



